2024-03-28T23:04:35Z
https://www.ije.ir/?_action=export&rf=summon&issue=11412
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
A New Approach for Vibration Analysis of a Cracked Beam
A.
Ebrahimi
Ali
Meghdari
M.
Behzad
Hamilton
Cracked Beam
Continuous Model
Natural frequency
2005
11
01
319
330
https://www.ije.ir/article_71597_a05705ca7364ae4f507a2368235af564.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
Unsteady Free Convection from a Sphere in a Porous Medium with Variable Surface Temperature
T.
Jalali
A.
Baradaran Rahimi
In this paper a transient free convection flow around a sphere with variable surface temperature and embedded in a porous medium has been considered. The temperature of the sphere is suddenly raised and subsequently maintained at values that varies with position on surface. The method of asymptotic expansions is applied for small Rayleigh numbers and then a finite-difference scheme is used to solve the problem numerically for finite values of Rayleigh numbers. Transient and steady-state flow and temperature patterns around the sphere are discussed in details and a comparison between numerical and analytical results has been presented.
transient
Rayleigh
Free Convection
Sphere
Porous medium
Local Nusselt number
2005
11
01
331
350
https://www.ije.ir/article_71598_b3935485f11634963fce9ea333708f96.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
A Computational Study of Oxygen Transport in the Body of Living Organism
N.
Kumar
Sanjeev
Kumar
Oxygen is an essential part of the living organism. It is transported from blood to the body tissue by the systematic circulation and large part of it is stored in the blood flowing in capillaries. In this work we discuss a mathematical model for oxygen transport in tissues. The governing equations are established assuming that the blood is flowing along a co-axial cylindrical capillary inside the tissue and has a constant partial pressure of oxygen. We solve the governing partial differential equations using finite element techniques. The main object of the present work is to investigate the effects of various assumptions such as neglecting axial diffusion, neglecting the effect of facilitated myoglobin diffusion etc.
Axial diffusion
Hemoglobin
Myoglobin
CO
axial cylindrical capillary
2005
11
01
351
358
https://www.ije.ir/article_71599_46dcb00e5cb5c2443ae7202506dcff77.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
Multi-Objective Lead Time Control in Multistage Assembly Systems (TECHNICAL NOTE)
S. M. T.
Fatemi Ghomi
A.
Azaron
In this paper we develop a multi-objective model to optimally control the lead time of a multistage assembly system. The multistage assembly system is modeled as an open queueing network, whose service stations represent manufacturing or assembly operations. The arrival processes of the individual parts of the product, which should be assembled to each other in assembly stations, are assumed to be independent Poisson processes with equal rates. In each service station, there is one machine with exponentially distributed processing time, such that the service rate is controllable. The transport times between the service stations are independent random variables with exponential distributions. By applying the longest path analysis in queueing networks, we obtain the distribution function of time spend by a product in the system or the manufacturing lead time. The decision variables of the model are the number of servers in the service stations. The problem is formulated as a multi-objective optimal control problem that involves three conflicting objective functions. The objective functions are the total operating costs of the system per period (to be minimized), the average lead time (min), and the probability that the manufacturing lead time does not exceed a certain threshold (max). The goal programming method is used to solve a discrete-time approximation of the original problem.
Queueing networks
Optimal control
production
Multiple objective programming
2005
11
01
359
370
https://www.ije.ir/article_71600_60e9b46af63f2e5fdfdee81ba510d197.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
A Parametric Study of the Behavior of Geosynthetic Reinforced Soil Slopes
M.
Vafaeian
R.
Qhaderi
H.
Hashemolhoseini
This paper presents the results of a number of computations using the 2D FEM to show the effects of significant variables on the behavior of geosynthetically reinforced earth slopes. The verification and reliability of the results are primarily examined through comparisons with experimental data available. The results seem to be quite acceptable and can be used with a high degree of reliability for predicting the relevant problems.The main variables studied are soil properties, slope geometry, and the properties of reinforcement elements, while the safety factor, deformation components, effect of geotextile stiffness, the shape and location of the slip surface are the main unknowns sought.
Reinforced earth slope
Geosynthetic
Effective Parameters
Safety factor
2005
11
01
371
389
https://www.ije.ir/article_71601_5bedd069ee7fef3470f6c95938e63bf1.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
Spatially Varied Flow Profiles in a V-Shaped Side-Channel
M.
Mohammadi
spatially varied flow
water surface profile
Hydraulic structures
surface drainage side
Channel
V
shaped channel
2005
11
01
391
400
https://www.ije.ir/article_71602_77fbc2e75a417c3216dd75c801555162.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
An Efficient Algorithm for General 3D-Seismic Body Waves (SSP and VSP Applications)
S. J.
Hashemi
M. K.
Ghasem Alaskari
Abstract The ray series method may be generalized using a ray centered coordinate system for general 3D-heterogeneous media. This method is useful for Amplitude Versus Offset (AVO) seismic modeling, seismic analysis, interpretational purposes, and comparison with seismic field observations.For each central ray (constant ray parameter), the kinematic (the eikonal) and dynamic ray tracing system of equations are numerically solved. Then, the ray impulse and the ray synthetic seismograms are efficiently computed. The reflected, refracted, critically diffracted, multiples and converted P-waves and/or S-waves are computed and evaluated at the ray endpoints. The central Ray Method application to two-dimensional models are investigated and comparison with seismic wave field are successfully done. Two examples of the ray field and synthetic seismograms for the complex models are presented here both for surface seismic profiling (SSP) and vertical seismic profiling (VSP).
3D
Seismic
SSP
VSP
synthetic seismograms
dynamic ray tracing
2005
11
01
401
412
https://www.ije.ir/article_71603_3fc3b98bf0f8e921bc8a4dbdf2964b31.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2005
18
4
Determination of the Rheological Properties of Hydroxyl Terminated Polybutadiene (HTPB) Mixtures With Energetic Materials and Presenting Empricial Models
M.
Edrissi
A.
Seifolazadeh
Rheological Properties Such as Viscosity (η), Shear Stress (τ), and Torque (M) of the mixtures of (HTPB) with Octagon (HMX), Hexogen (RDX), and 2, 6 Diamino-4-Phenyl-1, 3, 5 Triazine (DAPTA) mixtures were measured. The experimental design was arranged for three factors at two levels (High and low levels). Temperature of the mixture (°C), Speed of the stirrer (rpm), Mixing Time (minutes) have been known to be effective in the quantity of Rheological properties. In this work, by using the appropriate equations the empirical model was presented for each property and mixture and the main effects on the responses were detected.
Rheological properties
HTPB/Energetic Materials Mixtures
Empirical Models
and Experimental Design
2005
11
01
413
420
https://www.ije.ir/article_71604_4d024b0af5b69a864ab214978108fedd.pdf